Creating a high definition digital image requires a large amount of data. As stated by John Wiseman in An Introduction to MPEG Video Compression;                 One of the formats defined for HDTV broadcasting within the United States is 1920 pixels horizontally by 1080 lines vertically, at 30 frames per second. If these numbers are all multiplied together, along with 8 bits for each of the three primary colors, the total data rate required would be approximately 1.5 Gb/sec. Because of the 6 MHz channel bandwidth allocated, each channel will only support a data rate of 19.2 Mb/sec, which is further reduced to 18 Mb/sec by the fact that the channel must also support audio, transport, and ancillary data information. As can be seen, this restriction in data rate means that the original signal must be compressed by a figure of approximately 83:1.        
Software video decoding is now a common function for multimedia computers, however, as it requires a lot of computational power, available resolutions and formats are currently limited. The MPEG video coding standards, the ITU-T Recommendations H.26x for low bitrate coding of motion video, and the JPEG still image coding all use the discrete cosine transform (DCT) and iDCT for energy compaction and decorrelation.
Thus, there is a need for a flexible and low cost solution to improve digital image compression through the use of an optimal iDCT.